Spiral scanning mechanism



Jan. 9, 1951 M. FRITTS 2,537,822

SPIRAL SCANNING MECHANISM Filed Dec. 24, 1945 2 Sheets-Sheet 1 3 .j If.i'. 2

29 I p 28 I l5 1 22 5 27 BI 82 as I 25 4 as BVJ ZMES MM ATTORNEY Jan. 9,1951 M. FRlTTS 2,537,822

SPIRAL SCANNING MECHANISM Filed Dec. 24, 1945 2 Sheets-Sheet 2 //v lE/VTOR M. FR/ 7' TS Q? 7% xm A T TOANE Y Patented Jan. 9 1951 UNITEDSTATES PATENT OFFICE Telephone Laboratories,

Incorporated, New

York, N. Y., a corporation of New York Application December 24, 1945,Serial N 0. 637,125

1 Claim.

This invention relates to radio signaling apparatus and morespecifically to a scanning mechanism for use in such apparatus.

The object of this invention is the provision of a scanning mechanism ofthe type above referred to whichwill be simple and in which a directiveelement is operated in a manner to generate a scanning field determinedby the operation of two shafts relative to each other.

In the drawing:

Fig. 1 is an elevational view shown with a number of operating parts invertical section;

Fig. 2 is a front elevational view;

Fig. 3 is a top view;

Fig. 4 is a partial top view shown with the directive element orreflector in an operated position;

Fig. 5 is a detail view looking in the direction indicated by the arrowson line 5-5 of Fig. 1; and

Fig. 6 is a diagrammatic view of the scanning field obtained by themovement of the reflector.

As shown in the drawing, the scanning mechanism of this inventionconsists of a base ll! formed with two upright Supports I l and I2,upright support ll having an inverted U-shaped portion I3 at its freeend serving in cooperation with upright support I2 for rotatablymounting as on ball bearings BI and B2, a hollow shaft l4 best seen inFigs. 1 and 3.

On one end of hollow shaft I4 is keyed a gear l5 meshing with a pinionI6 keyed on the armature shaft of a motor I! secured to the base [0 asby a number of bolts l8, while on the opposite end of hollow shaft 14 iskeyed a forkshaped member 19, the shaft I4 and member 19 being rotatedthrough the operation of motor l'l, pinion l6 and gear l5 keyed as abovementioned on hollow shaft l4.

The fork-shaped member I9 is formed with a pair of arms 20 and 2|extending laterally therefrom and havingbearing portions in which isjournaled a shaft 22. On one end of shaft 22 is keyed a worm gear 23best seen in Fig. 2, meshing with a worm 24 carried or formed at one endof a hollow shaft 25 mounted in position concentric to hollow shaft l4and supported at one end by support ll, shaft 25 being-held fromrotation by a plate 26 secured to upright supports II, as by a number ofscrews 21, best seen in Figs. 1, 3 and 5, and having a fork-shapedportion fitted over two opposite sides of a square-shaped portion formedat the end of shaft 25 for preventing its rotation as would be impartedby friction between this shaft and the shaft l4 and the friction betweenthe worm 24 and the worm gear 23 while in operation.

To the end of shaft 22, opposite the worm gear 23, there is securelymounted a disc member 28 provided with a crank pin 29 serving forpivotally mounting a bell crank 30, the opposite end of which is pivotedto an arm 3|, best seen in Figs. 2, 3 and 4, formed with a head-piece Hin turn pivoted on a spindle 32 secured to the prong P of thefork-shaped member l9. Head-piece H in cooperation with a head-piece HI,pivoted on a spindle 34, secured to the other prong of forkshaped memberl9, serves for mounting a parabolic reflector 35 having a rim portion 36clamped between similarly shaped projections S and SI formed with thehead-pieces H and HI while the reflector 35 is formed with anoblong-shaped opening 31 through which projects the so-called emitter orantenna 38 connecting with a coaxial line (not shown) in the hollowshaft 25.

In the operation of the scanning mechanism of this invention, theoperation of motor I! is effective to rotate the hollow shaft I4 and thefork-shaped member l9 carried thereby through the engagement of pinionIS with gear [5 keyed to the hollow shaft [4. The rotation of forkshapedmember I9 is effective to rotate the parabolic reflector. 35, whilecausing the rotation of shaft 22 through the engagement of worm 23carried by the shaft 22 with the worm 24 carried by the hollow shaft 25,which is held against rotary movement by the forked plate 26. Rotationof shaft 22, and that of the crank formed by disc 28 and the pin 29which connects with the bell crank 30, is effective to impartreciprocating movements to the head-piece H and thereby to the reflectorfrom the position shown in full line, to the position shown in dottedline in Fig. 4 for each complete turn of the shaft 22 to cause thereflector 35 to generate a scanning field representing a spiral, asshown in Fig. 6, the pitch of which is dependent upon the speed ratiobetween the worm 24 and worm gear 23 for any given speed at which theparabolic reflector may be rotated.

What is claimed is:

A mechanical driving apparatus comprising a support, a first hollowshaft rotatably supported in said support, a yoke secured to said hollowshaft, a fixed hollow shaft extending from within said first hollowshaft and into the space between the arms of said yoke, a worm gear onsaid fixed shaft, a counter-shaft rotatably supported in said yoke, aworm wheel secured to said counter-shaft and in mesh with said wormgear, spaced levers pivotally supported on arms of said yoke and covoperating to support a paraboloid movable member having a transverseslot therein, a rigid member extending through said fixed hollow shaftand through said slot, and a crank and lever system forming a mechanicaldriving connection between said counter-shaft and at least one of saidspaced levers.

MORRIS FRITTS.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,083,242 Runge June 8, 19372,231,929 Lyman Feb. 18, 1941 2,407,305 Langstroth et al. Sept. 10, 19462,410,831 Maybarduk et a1. Nov. 12, 1946

